Biomedical subjects
Publications and source records attributed to G Ryge.
A total of 96 composite resin restorations were placed in primary molars. After 4 years, 44 restorations were examined. The wear rate was similar to that of enamel in primary molars. The material had excellent radiopacity and color-matching properties.
The restorations were evaluated at baseline, and at 6, 12, and 24 months by two trained examiners. In the system used, the highest, most desirable rating is Alfa. Of the restorations evaluated at 24 months, 99% had Alfa ratings for color match, 87% had Alfa ratings for no discoloration at cavosurface margins, and 86% had Alfa ratings for no loss of anatomic form. In addition, 75% of the restorations had Alfa ratings for margin adaptation, and 91% had Alfa ratings for no recurrent caries at the 24-month evaluation. In conclusion, the light-cured composite resin restorative material functioned well at the 12- and 24-month evaluation periods, when used in primary molars.
A group of 150 patients who had received extensive restorative treatment 5 years prior to this study was selected at random from the Swedish Dental Insurance System records in Malmo. Of the 133 respondents to a questionnaire, 109 participated in a clinical evaluation of 891 restorations including 498 crowns, 232 pontics, 6 removable partial dentures, and 155 adjacent or opposing metallic restorations. The clinical evaluation was performed by two trained examiners by means of the CDA quality evaluation for dental care. Ninety percent of the crowns and pontics, 80% of the adjacent or opposing metallic restorations, and all six partial dentures were rated satisfactory. Twenty-three percent of the crowns, 49% of the pontics, 17% of the adjacent or opposing restorations, and half the partial dentures rated in the range of excellence. Not acceptable ratings for crowns included 3.4% T ratings and 6.6% V ratings. For pontics, the corresponding percents were 9.5% and 0.4%, respectively. T ratings were in most cases indicative of overcontouring, whereas V ratings for crowns were usually given because of secondary caries. Marginal periodontitis was mainly associated with not acceptable ratings but was also observed in connection with satisfactory restorations. Only 2% of the restorations had been lost during the 5-year period after insertion.
The present study assessed the predictive value of an indirect metric method for the early detection of margin defects of amalgam restorations, relative to results using a direct clinical method. The material consisted of plaster casts of amalgam restorations taken at 1- and 2-yr examinations of four different amalgam-treatment combinations. The widest margin defect of each restoration was measured in a dissection microscope equipped with a metric scale in the ocular. The ranking order obtained from the metric measurements of the different amalgam-treatment combinations after 1 and 2 yr was compared with that obtained from the direct clinical evaluation after 2 yr. Finally, the rank order of those restorations rated Alfa (no visible evidence, along the margin, of a crevice (ditch) into which an explorer will penetrate) at the 2-yr clinical examination was studied in relation to the 1-yr metric measurements. For the total material, the rank order based on the metric measurements of the margin defects of the four amalgam-treatment combinations agreed with that obtained with the clinical rating. In the 1-yr data, where the metric technique was applied only on the restorations rated Alfa at the 2-yr clinical evaluation, the order of two neighboring combinations was reversed; otherwise the same rank order was obtained. It is recommended that the clinical performance of new brands of amalgam alloy are tested in short-term, small-scale studies using the metric evaluation technique, before more extensive field studies over longer periods are instituted, in order to sort out unsatisfactory materials and treatment techniques at an early stage.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Margin adaptation of dental amalgam restorations made from traditional vs. dispersion-type alloy was compared by clinical evaluation with the reference to plasticity of the mix at insertion. Also, variations in sealing properties were assessed for precondensed and not-precondensed amalgam mixes of both alloys. The data presented confirm the clinical superiority of amalgam made from dispersed type alloy. A higher plasticity tended to result in less margin deterioration for amalgams of the traditional type alloy. In vitro leakage with the dispersion type amalgam far exceeded that of the traditional amalgam.
An epidemiological study was performed in 250 persons who five years previously had been treated with extensive metallic reconstructions. To gain representative information these persons were selected at random from three Local Social Insurance Offices in different parts of Sweden. Those person, who in a questionnaire reported symptoms that could be alleged to have been caused by oral galvanic actions, were offered free clinical examination including quality evaluation and free measurements of potentials and polarizations of the metallic dental restorations. Persons from a subgroup to this study not suffering from any oral discomforts were chosen as a control group. Comparisons between the two groups were made in regard to current creation at metallic contacts, clinical quality and mucosal conditions. In none of the statistical analyses performed, differences could be shown between the groups. A tendency to higher amounts of restorative care at comparatively lower level of technical quality could, however, be noticed in the group of persons with oral symptoms which they themselves associated with oral galvanism.
In preparation for internordic studies of the clinical performance of selected restorative materials, 11 clinicians from Denmark, Finland, Norway and Sweden were selected to participate in two clinical training sessions. The first of these sessions consisted of lectures on clinical research methodology, the content of a research protocol and specific description of the criteria to be used for clinical evaluation of Color Match, Cavo Surface Margin Discoloration, Anatomic Form, Margin Adaptation, and Caries. Demonstrations were also given in the clinical evaluation procedures. Using a rotation system at both the training sessions each participant alternatively served as patient recorder and examiner. The participants examined and rated a larger number of restorations independently in teams of two. The results of the performed examinations showed the overall agreement between all pairs to exceed 85%. The results of this study indicate that after a short introductory course, scientifically non-experienced senior clinicians can be trained to use the described system at a comparatively high overall level of precision.
Marginal degradation of amalgam restorations has been evaluated using a direct clinical technique and three indirect clinical assessments. Ratings of the same restorations indicated a fair comparison between the results using the different techniques. Two photographs corresponding to the 'worst Alfa' and the 'best Charlie' in the FDI Recommendation (1977) for clinical comparison of restorative materials are presented.
Criteria for the evaluation of the physical and chemical properties of dental materials have been available for many years. However, the final decision about the acceptability of a dental restorative material for use in the mouth can only come from clinical observation. This paper attempts to set out a systematic approach to the clinical assessment of restorative materials by posing a series of questions, to each of which an answer Yes or No can be given. The system makes provision for reaching decisions on marginal adaptation, restoration and preservation of anatomic form, protection against recurrence caries, and in the case of materials used in anterior restorations, colour match and cavo surface margin discoloration. Using these criteria, restorations can be classified into four categories: those within a range of excellence, those which although showing minor deviations from the ideal are nevertheless acceptable, those which should be replaced for preventive reasons to avoid the likelihood of future damage and those which require immediate replacement.
One hundred and forty-three patients ranging in age from 5 to 8 years participated in a pit and fissure sealant study using a half-mouth design. At the end of 18 months, for all permanent first molars, there was a 75.9% effectiveness with a net gain of 82, which was statistically significant. The sealant was present on the surfaces to which it was applied in 74% of the teeth. Application time was 8 minutes per quadrant and 5.5 minutes per tooth. The effect of treatment was similar to that reported for an unfilled BIS-GMA sealant in patients with similar teeth and similar ages. Loss of sealant from the permanent maxillary first molars did not appear to contribute to the initiation of dental caries. However, in 6 of 38 mandibular tooth surfaces, sealant loss may have been a factor.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.